This invention pertains to preventing writing materials from being used in devices for which they are not authorized.
Devices that use printing or copying technologies, such as printers and copiers, are commonly sold in one of two different formats. In one format, the devices are intended to be used with metered cartridges. Using metered cartridges, the customer does not purchase the cartridge itself (or pays a nominal amount), but rather pays a certain charge per sheet printed or copied. In the other format, the devices are intended to be used with unmetered cartridges. The customer purchases the unmetered cartridge, but does not pay anything per individual sheet printed or copied.
Because any given device can be used with either metered or unmetered cartridges, there are usually no physical differences between metered and unmetered cartridges. For devices using metered toner cartridges, the device itself tracks the number of sheets printed or copied, so that the appropriate charges can be computed. The expectation is that customers will use the appropriate type of cartridge based on their contract.
Unfortunately, whether by design or by accident, sometimes metered cartridges are used with devices that are not expecting metered cartridges. Because the device is not expecting a metered cartridge, the device does not count the number of sheets printed or copied. And because the cost of the metered cartridge is generally less than the cost of an unmetered cartridge (the assumption being that the difference in cost will be made up in the per-sheet charges), the customer ends up paying less for the consumables than expected by the seller. Such misuse of metered cartridges in unmetered devices is termed “leakage”.
Leakage can occur in a number of different ways. A customer with both metered and unmetered devices can order metered cartridges as needed for all of the customer's devices, and use them even in unmetered devices. Or, a vendor (a middleman between the customer and the manufacturer) can order metered cartridges on behalf of a customer that uses both metered and unmetered devices, then sell the metered cartridges to the customer as unmetered cartridges, making a profit on the transaction (as the unmetered cartridges would be sold for a higher price than metered cartridges). Or, the vendor can take advantage of the fact that one customer uses a metered device to order cartridges to order metered cartridges for multiple customers, selling the excess cartridges to other customers.
The invention addresses these problems and others in the art.